bedford tk

[darren taylor]

hello i am new to the forum can anyone help i have a bedford tk 10 tonner on air over hydrolic brakes i have stripped them down and can not remember how to rebuild does anyone have a diagram i do not know which way round shoes fit with trailing and leeding edges many thanks darren

[G-CPTN]

Be patient - I have just this minute come in (been fishin').


I will reply as soon as I can find my diagrams.

Hopefully this evening . . .

[G-CPTN]

Here goes (I will assume that you have dissembled the brakes and are ready to reassemble them. If you need further information, just ask.
I presume that the wheel cylinders are still in situ - if you need instructions to install these just ask.) :-

1. Lightly smear the faces of the links, spacers and anchor plate with the approved grease (Duckhams Keenol). IIRC Keenol was a white waterproof grease, now discontinued, but see:- http://marinestore.co.uk/Ramonol_Whi...lacement_.html

2. Assemble the links and friction springs to the brake shoes as shown:-
http://i24.photobucket.com/albums/c1...ps9b778af1.jpg
noting that the heads of the bolts must be adjacent to the backplate when the brakes are installed on the vehicle.
Tighten the link bolt but leave the nut unpinned.

3. Check the tension of the friction springs as follows:-
a) Secure the brake shoe in a vice using soft jaw clamps and position the links at their maximum point of travel without over-riding the friction springs.
b) Install a bolt through the holes at the outer ends of the links, and, using a spring balance, check the load required to move the links:-
http://i24.photobucket.com/albums/c1...pscd4351fa.jpg
If the friction load is less than the specified limit (12 lb) renew the springs.

4. Slacken the link bolts sufficiently to assemble the links to the anchor plate.
Align the links and friction springs, and tighten the bolts.
Secure the nuts with split pins.

Note the following:-
1. Engage the leading shoe in the shoe support before tightening the anchor plate nuts.
Tighten the front anchor plate nuts and shoe support bolts to the specified torque (37 lb ft).

2. Install the push rod anchor springs and the shoe return springs as shown:-
Note that the illustration shows the left hand (rear) brake - the right-hand brakes will be mirror image with the thicker leading shoe lining towards the front of the vehicle!
http://i24.photobucket.com/albums/c1...ps9b778af1.jpg
ensuring that on the front brakes the spring with the greater number of coils is attached to the leading shoe.
Assemble the right-hand front brake shoe return springs behind the shoes. (I've checked that this is what the manual says! This might not apply to 4x2 vehicles.)
All shoe return springs must be assembled with the squared end attached to the brake shoe:-
http://i24.photobucket.com/albums/c1...ps6e06a63e.jpg

3. Back off the shoe adjustment and install the hub and drum.

1. Lubricate the outer hub bearing with the approved grease and insert the complete bearing, thin end of the race first, through the inner end of the hub, and tap the outer race squarely into the hub until it is clear of the retaining ring groove.
Assemble the retaining ring in the hub groove, ensuring that it is correctly seated.
Insert the drift and tap the bearing outer race into contact with the retaining ring.
Note that these instructions are for a 4x4 vehicle front hub. No specific instruction is given for the rear hubs.

2. Locate the outer race of the inner bearing in the hub, thick end first, and tap home squarely against the hub recess shoulder.
Pack the inner race and rollers with the approve grease, and assemble to the hub.

3. Lubricate the seal and refit with the lip towards the hub.
Press in until the face of the seal case if flush with the hub.

4. Clean the contact faces of the brake drum and hub and assemble the drum to the hub.

5. Smear the threads with Loctite Grade AVV and replace the drive sleeve studs in the hub.

As stated, the above instructions are from a 4x4 manual, and no specific instructions are given other than:-
The rear hubs are similar to the front and the same service procedure may be adopted.

Install the rear axle shafts applying a smear of jointing compound to the mating surfaces.
Lock the nuts with Loctite grade AVV. Rear axle shaft stud torque 25 lb ft.

4. Adjust the brakes.

To adjust the brakes, jack up each wheel in turn and proceed in the sequence given below.
When adjusting the rear brakes, skotch the front wheels and release the parking brake.

1. Charge the system to operating pressure.

2. Turn the shoe adjuster anti-clockwise until the drum is free to rotate.

3. Turn the front shoe adjuster clockwise (see fig N21) until the shoe is hard against the drum.
Centralize the shoe by applying heavy pressure to the brake pedal, then release the pedal.

4. Back off the adjuster until the shoe is just clear of the drum, ie so that the wheel rotates freely without the shoe rubbing.

5. Repeat operations 3 and 4 on the rear shoe adjuster.
Repeat for each wheel in turn.
Illustration of brake adjusters:- http://i24.photobucket.com/albums/c1...n/IMGP8511.jpg

6. Push in the indicator rod on the air actuator until it contacts the piston.
The indicator rod is about the diameter of a wire coat-hanger wire (from memory) and should stick-out along the axis of the air servo.
See item 23 on this illustration:-
http://i24.photobucket.com/albums/c1...n/IMGP8509.jpg
If your vehicle is very old, the design of the servo might be different to the above illustration.